1. Field of the Invention
This invention relates to vacuum cleaners. In one of its aspects, the invention relates to a vacuum cleaner having two stages of filtration. In another of its aspects, the invention relates to an extraction cleaner that has two stages of filtration. In yet another of its aspects, the invention relates to a multiple use vacuum cleaner that is adapted for dry vacuuming, extraction, and bare floor cleaning.
2. Description of the Related Art
Vacuum cleaners are well-known household cleaning devices that are used to clean dirt and debris from rugs and carpets. Vacuum cleaners commonly use a motor-driven suction fan to draw dirt-laden air into the unit, filter the air through some filtering means and exhaust the relatively clean air back into the room. One type of filtering means is a filter bag, wherein dirt-laden air is drawn into a porous bag which traps dirt and allows relatively clean air to exit through the walls of the bag to the environment as disclosed in U.S. Pat. No. 5,544,385 to Jailor et al. However, fine dirt particles can escape through the walls of the bag, thus recontaminating a room. Also, bags must be changed regularly when they are full, which is a time-consuming operation and requires a user to have a supply of new filter bags at hand, which adds additional expense to a vacuum cleaner. Changing filter bags is often a messy operation during which some of the collected dirt can become reentrained in the environment of a room.
An alternative to vacuum cleaners having filter bags as a filtering means are bagless vacuum cleaners which use cyclonic separators to separate dirt from the air using centrifugal force as disclosed in U.S. Pat. No. 4,571,772 to Dyson. Dirt-laden air is introduced into a cyclone separator, usually through a tangential opening near the top of the separator, and flows through the separator in a well-established cyclonic pattern. Dirt is separated from the air and is thrown outwardly against the walls of the separator where it falls down into a collection chamber. Relatively clean air then exits the separator and is exhausted to the environment. As with a bagged vacuum cleaner, this exhausted air may still contain fine dirt particles that were not filtered out in the cyclonic separator. And while the collection chamber for a cyclonic vacuum cleaner can be removed from the vacuum cleaner and emptied with relative ease compared to the changing of a filter bag, the dumping operation can also allow dirt particles to be reentrained in the air.
A third type of filtering means is the use of a water bath to remove dirt from air flowing through a vacuum cleaner as disclosed in U.S. Pat. No. 4,251,241 to Bothun. Dirt-laden air that is drawn in by the suction fan is ported through an air inlet such that it is directed through a reservoir of water. Heavier dirt particles are captured by the water while the filtered air exits the water bath and is exhausted to the environment. The reservoir of water may be a detachable chamber to facilitate disposal of the dirty water after vacuum cleaning. Emptying the reservoir of dirty water is more hygienic in comparison to changing filter bags or emptying a collection chamber filled with dry dirt, since the dirty water can be poured into a sink or drain without any particle reentrainment into the environment as is observed when pouring out dry dirt.
Even with regular vacuum cleaning, carpets often require more intense cleaning to remove stains or dirt that is deeply ingrained into the carpet pile. One way of deep cleaning a carpet is referred to as wet extraction and can be accomplished distributing a cleaning solution over the carpet and removing the spent cleaning solution by vacuum suction. Many homeowners choose to have this done professionally since they do not have the necessary equipment for deep cleaning a carpet or do not want to purchase a wet extraction machine that will only be used a few times a year. Some vacuum cleaners can be converted into a wet extraction cleaner to combine the functions of dry vacuuming and carpet deep cleaning as disclosed in U.S. Pat. No. 5,287,590 to Yonkers et al. These devices often have many complicated parts that must be interchanged in order to perform each function.
Many homes include bare floors such as linoleum, tile, or hardwood in addition to carpeted surfaces. Most homeowners have vacuum cleaners, whether bagged, bagless, or water-filtered, that are adapted for carpeted surfaces and may damage bare floors, thus additional cleaning devices are required. Bare floors commonly require multiple implements in order to achieve a thoroughly clean surface. Usually, a broom and dustpan are first used to gather and remove loose, dry particles from the floor. However, it is almost impossible to transfer all the dirt onto a dustpan and consequently, some dirt remains on the floor. After sweeping, a cleaning liquid is applied to the floor, most commonly by a sponge or rag mop. A mop is a very efficient cleaning means but when it requires more cleaning solution, the mop must be returned to a bucket to absorb additional cleaning solution to be reapplied to the floor surface. The repeated dipping of the mop into the bucket quickly dirties and cools the cleaning solution rendering the cleaning process less effective. After mopping, some cleaning solution remains on the floor surface to air dry, and the duration of time required for the bare surface to completely dry depends on the amount of residual solution on the floor and the relative humidity in the room. During the drying period, foot traffic must be avoided since dirt and other debris will easily adhere to the damp floor surface.
Some household cleaning devices have been developed that combine carpet dry vacuuming and deep cleaning with bare floor cleaning to eliminate the need for multiple cleaning devices for different types of cleaning. These cleaning devices are referred to as wet/dry vacuum cleaners or three-in-one cleaners. Many of these combined cleaners require disassembling the unit or changing certain parts such as filter or collection means to switch between cleaning types. For example, U.S. Pat. No. 4,287,636 to Brazier discloses a vacuum cleaner that can be used for both dry vacuuming and wet extraction. However, a filter unit for dry vacuuming must be exchanged for a reservoir unit when a user desires to use the vacuum cleaner for extraction.
The present invention solves the aforementioned problems by providing a single cleaning machine with a water bath filter in combination with a cyclone separator that can be used on both carpet and bare floors for both dry and wet pickup.